1. Technical Field
The present invention relates to a timing signal generation device, an electronic device, and a moving object.
2. Related Art
A timing signal generation device which performs synchronization with a precise timing signal included in a satellite signal and the like from, for example, a global positioning system (GPS) satellite, causes an oscillator such as a crystal oscillator or an atomic oscillator to oscillate, and thus generates a highly-precise timing signal has been known (for example, see JP-A-2012-129879).
In such a timing signal generation device, when, for example, a situation in which reception of the satellite signal is not possible occurs, generally, synchronization processing of synchronizing a clock signal of the oscillator with a timing signal included in the satellite signal is stopped, and the oscillator is caused to perform self-running, and thus a timing signal is generated. During self-running of the oscillator, phase shift between the timing signal included in the satellite signal, and the clock signal of the oscillator occurs depending on the time length thereof. Thus, when a situation in which receiving a satellite signal again is allowed occurs, the synchronization processing is restarted. However, at this time, it is necessary that the phase of the timing signal included in the satellite signal is rapidly synchronized with the phase of the clock signal of the oscillator.
For example, the synchronization signal generation device disclosed in JP-A-2012-129879 includes a GPS receiver which generates a GPS reference pulse from a signal received from a GPS satellite, an oscillator which generates an internal frequency signal, a divider which divides the internal frequency signal so as to generate an internal pulse, a synchronization unit which compares the GPS reference pulse and the internal pulse, and synchronizes the internal pulse with the GPS reference pulse, and a control unit that determines a loop time of the synchronization unit when a state comes back to a GPS lock state from a hold-over state, in accordance with a state of a base station. In the synchronization signal generation device, when the state comes back to the GPS lock state from the hold-over state, the control unit sets the loop time of the synchronization unit to have a small value, and thus it is possible to rapidly remove phase shift.
In the synchronization signal generation device disclosed in JP-A-2012-129879, in a case where a phase difference between the GPS reference pulse and the internal pulse is large, when the loop time of the synchronization unit is set to have a small value, a problem in that an output frequency largely fluctuates may occur.